Weeds affect many lawns at some time. A use of chemical means to control these weeds, however, may damage or destroy the existing lawn. Although most broadleaf weeds are easily eliminated from lawns by treatment with commercially available broadleaf weed killer, grassy weeds are much more difficult to remove. Annual grassy weeds such as crabgrass, grassburs and winter grasses may be controlled by application of pre-emergent weed killers in late winter and again in late spring without damage to existing lawns. Perennial grassy weeds such as dallisgrass and johnsongrass may be controlled in bermuda lawns by careful and repeated application of MSMA or DSMA in late spring or early summer. Most treatments for perennial grassy weeds in St. Augustine lawns, however, are ineffective. Although spot treatment with MSMA, DSMA or glyphosate may kill the weeds, it will also kill large patches of the St. Augustine lawn.
Many weed pullers have been developed to remove weeds from lawns or gardens where chemical means are ineffective. Some of these weed pullers have jaws or blades that pinch or grab the upper part of the weed and attempt to pull it from the soil. These weed pullers may be effective against individual weeds in sandy or loamy soil. They are ineffective, however, in dense soil such as clay against weeds with extensive root systems such as dallisgrass and johnsongrass. Often the grasping action of the jaws or blades damages a weed so that a subsequent attempt to pull the weed simply results in decapitation. Alternatively, the weed pullers with prongs or spikes may not effectively grab the weed and lose a grip on the weed during the attempted extraction. Another problem with pronged or forked weed pullers arises due to the space between the prongs or forks. When extraction of weed groups is attempted, the prongs or forks may separate the weed into may small sections that slip between the prongs or forks and remain firmly rooted in the ground. Yet another problem with these weed pullers is that they require the user to constantly bend and lift to extract the weed from the ground. Rotary weed pullers present yet another problem. They twist the top of the weed with respect to the weed's root system and may decapitate the weed leaving much of the root system in the ground. A final problem with many of these weed pullers is due to ineffective leverage provided for extraction even if the weed is properly grasped. Thus, repeated use is often difficult and exhausting work.